Mortising machine



Aug. 11, 1931. R. 5. BROWN 1,817,910

MORTI S ING MACHINE Filed Sept. 11, 1928 9 Sheets-Sheet 1 Aug. 11, 1931. R. 5. BROWN I MORTISING MACHINE Filed Sept. 11, 1928 9 Sheets-Sheet 2 lNVENTOR. ifilw'ww A TTORNEYS.

Aug. 11, 1931. R. 5. BROWN MORTISING MACHINE 9 Sheets-She't 3 Filed Sept. 11, 1928 INVENTOR. B 5.

ATTORNEYS.

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MORTISING MACHINE Filed Sept. 11. 1928 9 Sheets-Sheet 4 i. R s m n m m W m T Q1, ww ,IIII. w N I A 1 Tl I; 1E ww 6 mw kw ww s :2 uu v q w mw J JH mw 1 on 211 1:: HI :1 1| WW II I MU H Ill I 8 p .1 b Q. MW mwm M W H u- Qm R Q s l m kw? Q m 6 mh. Q N i- Q +1 I m an wm m i? J\ Aug. 11, 1931. R. 5. BROWN MORTISING MACHINE Filed Sept. 11, 1928 9 Sheets-Sheet 5 INVENTOR.

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Aug. 11, 1931. R. 5. BROWN MORTISING MACHINE Filed Sept. 11, 1928 9 Sheets-Sheet 6 INVENTOR. W 5. 55m

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Aug. 11, 1931. R. 5. BROWN 7,

I MORTISING MACHINE Filed Sept. 11. 1928 9 Sheets-Sheet 7 INVENTOR. W ma w A TTORNEYS.

Aug. 11, 1931. R. 5. BROWN MORTISING MACHINE Filed Sept. 11, 1928 9 Sheets-Sheet 8 Law/ 23 INVENTO W 5. 55mm; M. mvw

ATTORNEYS.

Filed Sept. 11, 1928 9 Sheets-Sheet 9 ATTORNEY Patented Aug. 11, 1931 1 STATES PATENT OFFICE ROBERT S. BRQXVN, OF NEV BRITAIN, CON NECTICUT, ASSIGNOB TO THE NEVV' BRITAIN g: JHACHINE CGMPJENY, fil NE'W BRITAIN, CONNECTICUT, 1i CC'EPQRATI'ON 9F CON- 7 NECTICUT MORTISING MACHINE Application filed September 11, 1928. Serial No. 305,177.

My invention relates to certain new and useful improvements in wood working machines and especially in so-called chain mortising machines. 7

Among the main objects of my invention are, to provide features of construction by which the mortising work may be rapidly and accurately performed, and by which a lateral as well as a depthwise cut may be made when mortises of greater length than would be produced by a single depthwise out are desired; also, to provide new and im-, proved features of construction by which the work of operating the machine is greatly simplified and this I accomplish by certain new features of construction by which the operation of the machine is controlled partly by a manual act and partly by the mechanical functioning of the machine itself.

" These and other objects will be apparent to the mechanic skilled in this art by a reading of the following description and an examination of the accompanying drawings in which I have shown'my invention in only one preferred form and in which drawings Fig. 1 is a complete side elevation of a mortising machine made according to the present invention;

Fig. 2 is a side elevation of the machine taken from the opposite side from Fig. 1, parts being shown in section to more clearly disclose their construction;

Fig. 3 is an enlarged side view of a part of the mechanism for raising the work support mounted on the base of the machine;

Fig. 4 is a sectional view taken upon the plane of line lof Fig. 3;

Fig. 5 is a side elevation of the latch means for retaining the work support in its elevated position;

Fig. 6 is a view similar to Fig. 5 with the parts in a different operative position;

Fig. 7 is a side elevation partly in section f the means for actuating the latch means for holding the work support in an operative position the parts being shown in the position assumed when the support is in its lower position;

Fig. 8 is a view similar to Fig. 7 with the parts shown in the position assumed when thesupport has been moved to its elevated position;

F 1g. 9 is a cross sectional view of the upper end of the machine showing the main driving shaft and the chain cutter;

F 1g; 10 is a sectional view taken through the dash pot employed in the machine;

Fig. 11 is an isometric view of the clutch actuating member of the feed mechanism;

Figs. 12, 13 and 1a are views of work operated upon by the machine; and

Figs. 15 and 16' are isometric views of the mechanism shown in F igs. 5 and 6.

Fig. 17 is an isometric view of the latch 91 shown in Figs. 4:, 7 and 8.

In the drawings.v 10 represents a column forming the base and frame of the machine. 11 is a horizontal shaft in the upper part of the column 10 carrying a pulley 18 driven by a belt 12 from any suitable source of power, such as a motor 14, which may be mounted within the column. 15 is a sprocket wheel on the shaft 11 for driving achain cutter 16.. The shaft is preferably supported on antifriction bearings 17-18. 19 is a cone pulley splined on the rear end of shaft 11 for driving the feed mechanism presently to be described. This pulley 19 may be held in place against a spacer 21 by a nut threaded on the end of the shaft which itself may form an additional step to the cone pulley. A look nut 22 for the nut 20 may be threaded on the end of the shaft 11.

23 are ways on the front of the column 10 on which is vertically movable the saddle part of a work support or carrier 24:. 25 represents the usual work table or holder which is suitably constructed for clamping thereon a piece of work which is to be mortised by the chain cutter 16 and which may be manually moved or adjusted laterally in the usual way. The support 24 and the work table carried thereby are supported by means of a nut 27 carried by a screw 26. The nut 27 preferably has a bevel gear 29 and may be rotated by a shaft 30 having a small pinion gear at its inner end meshing with the bevel gear 29. Thereby the nut 27 may be moved on the screw 26 for adjusting the initial position of the work table.

The table itself is moved upwardly by the feed mechanism that I am about to describe. The screw threaded rod 26 is provided with arack 31 at its upper end in which meshes a segmental gear 32 on a lever 83 which is pivoted on bearings in the column 10 by the shaft 34. The lever 33 is actuated by means that I shall now describe so as to positively move the rack 31 a c. the work table u ardlyduring the mortising operation. The cone p ley 19 by belt 35 drives cone pulley 36 whic 1 is on a short horizontal shaft 3? on one side of the column 10. The shaft 3? nas a term 38 engaging a worm wheel 39. The worm wheel 39 is secured to a member e2 rotatably mounted on a horizontal shaft 40 exten-zling from side to side of the column 10. \Vithin the member 42 is pressed a pair of shafts 43 upon each of which is loosely mounted pair of planetary differential pinions The pinions of each pair are connected to each other and are of slightly different tooth numher. One pinion of each pair engages a sungear 44- fixedly secured to the shaft 4:0, v-ihile the other pinion of each pair enga i a sun gear is fixedly secured to sleeve or qu rotatable on the shaft 40. The outer e is of the shafts 43 are supported within a housing ring 4-2". The worm wheel 39, the member and the ring -12 are suitably held together by bolts L2 one of which is shown in Fig. The shaft l0 is mounted in a housing i9 suitably secured in an opening in the column 10. The parts 49 and 50 form a housing for the worm gear 39, the planetary mechanism, the quill 4:6, and the shaft 40. Slidable on the shaft 40, but rotatable therewith by reason of flattened engaging portions on the shaft and disks, is one set of disks of a multiple dish brake 47, the other set cooperating therewith being held from rotation by a stationary bolt or stud 48.

The above mechanism forms a differential planetary mechanim which acts as a clutch for transmitting power from the shaft 37 to the quill 46. lVhen the brake disks are forced together, the shaft 4.0 and the sun gear 44; fixed thereon are held against rota.- tion, and the quill 46 will be slowly driven through the medium of the planetary mechanism. lVhen, however, the brake released, said shaft l0 and sun gear ll thereon are free to rotate. and no power will be transnn i. to the quill through said planetary mechanism. Part 51 is supported by the column 10 and forms a h using for the brake ii.

The brake a is operated follows: Pivotally mounted on the part 51 is a bell crank lever 52, a part of which is adapted to bear a he outer disk of the brake a7. The outer end of said lever is connected by link 03 to a spool slidably mounted on the outer end of the shaft 40 and operated by abell crank lever 56 ha *ing pins 61151515,? ing a collar 55 in the groove part of the spool 54. 78 is a yoke fixedly attached to a movable rod The yoke 78 straddles a pin 56 on the side of the bell crank lever 56 which is pivoted at 59 so that as the rod 73 is moved up and down, the bell crank lever will be operated to in turn apply and release the brake Rod 73 is connected at its lower end to a foot treadle 7O pivoted at 71 to the base of the column 10. 7 T2 is a counterl alance weight adjacent the lower end of the rod 73 serving to normally pull the rod downwardly and elevate the foot treadle 70. 1V hen the foot treadle T0 is fully depressed, the rod 78 will be elevated sufliciently to apply the brake l? and hold the shaft 40 with its sun gear as against rotation, thus causing the planetary go: 1' to transmit a r tary movement to the quill 4G.

The quill 46 has fixed thereon a pinion 5 which a segmental gear 58 on the rear end of the lever 33, the front end of said lever having the aforesaid segmental gear which meshes with the rack 31. lVhen the quill 4-6 is rotated by the planetary gear, movement will be imparted to the lever 33 in a direction to raise the work table.

If the operator keeps the threadle depressed, the upward feeding of the work table will be automatically stopped at a predetermined upward limit and the table will be retained in that position by means which l' shall now describe. On the rod 78 is a ollar Tel adjusta-bly fastened by a set screw 1' The position on the rod 73 at which the collar Tl is fastened determines the length of stroke of the work support Q l and hence the dcpthwise cut of the mortise. The shaft is fixedly attached to the member 33 and carries an arm 77 fixedly at'ached to its outer end. The 7?" is pivotally attached to a pivot pin on a sleeve 76 which is slidable on the rod 73. As the work support 24 moves upward the sleeve 76 slides down on the rod "('3 oscillating the rod slightly about a pivot 73 w" ich connects the rod and the treadle 70. lVhen the raising mechanism has operated and the tool has cut the required depth, the sleeve 76 strikes the collar 74 and moves the rod 73 downward a slight distance rocking the bell crank lever 56 and disenthe brake 4:7. ."xs the member 33 is being moved by power transmitted through the planetary gear mechanism during the raising of the work support, this slight downward motion of the rod '73 will take place against the pressure of the operators foot upon the treadle 70.

Automatic means are provided for holding the work support in its elevated position as long as the treadle is depressed. Pawls 80 are pivotally mounted on the housing 4:9 and have their outer ends suitably pointed to engage the teeth of a ratchetwheel 81 which may be formed integrally with the quill e6. lVhen engaged with the ratchet-wheel 81, the pawls 80 hold quill lG from clockwise rotation and prevent the work support- 24 fronr descending The awls 80 are made of slightly diffierent 'ength so that one or the other will drop-into engaging position with a tooth on rachetwheel- 81 when counter-clockwise rotation of the ratchet-wheel ceases, without permitting material clockwise movement of the pinion 57' and downward movement of the work support 24.

Means are provided so that when: the tread le is released, the pawls Till be raised out of engagement with the ratchetwheel St toenable the, work support 24 to descend underthe influence of its own weight.- J ournaled in the column 19 is anoscillating shaft 92 to which is rigidly attached a lug 87, a rocker-arm 99, and the radially extending' Weighted member 82; When the operator releases the treadle 70, the yoke 78 is lowered and therewith an extension 88 on said yokewhich carries an adjustable screw 89.. This screw 89 strikes the rocker arm 90 andthrows the weighted member 82 to the right beyond its vertical position, whereupon its continued movement to the right by gravity causes the lug 87 to strikethe heels of the pawls- 8'0" and raise them out of engagement with the ratchet-wheel 81. The quill 456 is then free to rotate and the work support 24 will drop under the influence of its own weight.

The fall ot the work support ischecked by a d'ash pot 28 attached tothe lower end of'the screw threaded rod 26'; The dash-pot 28 slides over a hollow piston 61- fixed to the col umn 10. The head of the hollow piston: 61: isprovided with an upwardly opening check valve 63normal-ly closed by a light spring 65.

; 66 is a cup washer" held in place by the part 64'. The lower end of the piston has one or more openings 62 provided with a screen 62 to" admit air intothe interior ot the piston. Air flows freely through the check valve 63' intothe space within the dash-pot 28 above the piston when the dash-pot is rising,- thus permitting free movement in anupward di rection of the rod 26. A vent 68 in the side wall of the dash-pot permits air to escapeso 57 as to allow the rod 26 to descend freely to-t'he point where the piston closes said vent; From this point on, aircan only'escape from" the dash-pot through a passage controlled by an adjustable needle valve 67 which may be so restricted by said valve as to provide an air cheek to slow up the descent of the work talile during said period.

A pawl latch in the form of. a bell crank lever 84 is pivoted to the frame by means: of the pivot 84*. The horizontal arm of the pawl latch 84 hasa notch 85 forming a shoulder which is adapted to engage-pins 86 on the pawls 80 when the pawls are raised" and thus hold the pawls- 80 out ofiengageinent with the ratchet-wheel during the downward motion oi the work support.

An automatic resetting mechanism is provided to automatically reset the weighted member 82 in its left position shown in Fig. 6 and thereby automatically release the pawls from the pawl latch Set so that they may again function automatically to engage the ratchet-wheel 81 at the end of the next upward stroke of the work support 2 1 (see F igs. 4 to 8). Fixedly attached to the shaft 921 is a radially extending member 93. A link 83. is pivoted at one end to the member 93 and has a tooth at its opposite end: which is adapted to engage with a tooth of the pinion 57. when the pinion 57 ceases rotation at the end. of the downward stroke of the work support 24.: T he position of the link 83 when the work support 24 is at its lowest position is shown in Fig; '2'. When the pinion 57 rotates to raise the work support, its coaction with the link 88 will push the link 83 and the weighted member 852 to the left beyond: the vertical: position of the latter. The weighted member 82 will then fall into its extreme left position (shown in Fig, 8 under the influence of gravity. During the latter part of this motion, a lug 94 on the link 83 will engage: with the hub of the member'9'3 to lift the tooth end of link 88' to the position shown: in Fig. 8.. hen the weighted member82" reaches its extreme left position, it coacts with an adjustable shoulder 95 on the upwardly extending arm of the pawl latch 84 so as to oscillate the horizontal arm ofthe pawl latch 84. upward and release the pa'wls 80 therefrom. The p'awls 80- are then free to engage with the ratchet wheel 81 at the end of the upward stroke of the work's-upport 24.

Suitable automatic means are provided for dropping the tooth end of the link 83 into engagement with a sufiiciently remote tooth of the pinion 57 so that a; partial rotation of the pinion 57 will suihc'e to move the weighted member 82' to the left past its vertical position.

In the form shown, this means comprises an arm 91' pivoted at 97 and having a laterally extending lug 98 at its free end which coacts with a pin 99 on the side of the link 83' to prevent the toothed end of the latter from too quickly engaging the pinion 57 when the link is moved from the position: indicated in solid lines in Fig. 8- to that indicated in solid lines in Fig. 7. On this movement, the pin 99rid'es over the lug 98 as indicated in dotted lines in Fig. 8 with the result that the toothed end of the link 83 engages a remote tooth on the pinion 57. W'hen' the weighted" arm. 82 moves from the position indicated in solid lines in Fig. 7 to that indicated in solid lines in Fig- 8, the pin 99 will pass under the lug'98 as indicated indotted: lines in Fig. 7,v the arm 91 momentarily risto permit the pin to pass- A. spring pressed plunger 96 coacts with the arm 91 to yieldingly hold it normally in the position indicated in solid lines in Figs. 7 and 8.

The machine operates as follows hen the treadle T0 is pushed down, the brake 47 is applied, causing the pinion 57 to rotate counter-clockwise and raise the work support 24. The rotation of the pinion 5'? will also push the weighted member 82 to the left of the position shown in Fig. 8. The movement of the weighted member 82 to the left will trip the pawl latch 84, releasing the pawls from the pawl latch and permitting the pawls to ratchet upon the ratchet-wheel 81, which is rotating the work support is being raised (see Fig. 6). The length of stroke of the work support, and hence the depthwise cut of the mortise, are controlled by the setting of the collar 74. hen the work support has reached the predetermined limit of its upward excursion, the arm 77 operates to move the rod 78 slightly downward against the pressure of the foot upon the treadle 70. This slight motion of the rod 73 oscillates the bell crank lever 56 sufficient to release the brake 47. As soon as the brake is released, the rotation of the ratchetwheel 81 ceases and the pawls 80 then engage the ratchet-wheel and hold it against reverse rotation, thus retaining the work support 2 L in its raised position.

When the operator releases the treadle 70, the counterbalance 72 operates on the rod 73 to move it downward. The downward motion of the rod will release the brake if it has not already been released automatically as just mentioned. As the rod 73 moves downward, the screw 89 coacts with the rocker arm to move the weighted member to the right. The movement of the weighted member to the right produces three separate effects. The first effect is to disengage the pawls 80 from the ratchet-wheel 81 (see Fig. 5), permitting the work support 24 to fall under the influence of its own weight, its fall being checked by the compression of air in the dash-pot 28. The second effect of the movement of the weighted member to the right is to allow the horizontal arm of the pawl latch Set to fall under the influence of its own weight, with the result that the pawl latchSsi engages with the pawls 80 and holds them out of engagement with the ratchet wheel 81 during the descent of the work support'and'nntil thetreadle 70'is nshed dew for the next feed stroke of the work support. The third effect of the movement of the weighted member 82 to the right is to move the link 83 to a position. where its toothed end will engage with a tooth of the pinion 57 (see Fi 7) when the rotation of the pinion ceases at the bottom of the stroke of the work support 24. Vhen the brake is again applied and the pinion 57 starts to rotate counterclockwise as shown in Fig. 7, the weighted member 82 will be reset in the position shown in Figs. 6 and 8, in the manner previously described.

After two or more adjacent cuts have been made to form a long mortise, the treadle 70 is held down after the last cut, thus keeping the work support 2% in its raise: P( i-iitl011,2lll(l the work holder 25 may then be moved laterally by hand. This lateral movement of the work holder causes the cutter to remove fillets such as shown in F i 13 as the end of the cutter travels across the bottom of the mortise. The operator then releases the treadle 70, thus disengaging the pawls 8 from the ratchet-whee til and the work support 24; fails to its lowest position.

I claim:

1. A mortiser compris' ig in combination, a base, a citter mounter thereon, a work sup port movably mounted on said base, a powerdriven machineeed mechanism for said support, means to automatical'y and positively lock the support a position with the cut ter engaged with the work, and means to release the support for movement from the cutter by gravity.

2. A mortiser comprising in combination, a a base, a cutter mounted thereon, a work support movable toward and from said cutter said support being moved away from said cutter by gravity, power-driven machine, feed mechanism for moving the support to ward the cutter, automatic means to release said feeding means when said support reaches a predetermined operative position, and automatic means to positively lock said support in said aredeteri'nined operative position.

3. A mortiser comprising in combination, a revolvable cutter, a work support, powerdriven machine, feed mechanism for moving one of said members toward the otaer, a trcadle for controlling said feed mechanism, means controlled by said treadle to release said feeding means and pennit said one member to move downward by gravity, and means to automati'ally and positively lock said one member in a predetermined operative positron.

l. A mortiser comprising in combination, a base, a cutter mounted thereon, a work support movably mounted on said base, feed mechanism for moving said support toward the cutter, a driving pinion for said feed mechanism, a clutch for rot "ng said. pinion, atrea-dle to opcrat saidcl' n,locl=:ingnieans for said driving pinion in one posi..on of said support, and means to release said locking means to permit movement of said sup port away from said cutter.

5. A mortiser comprising in combination, a base, a cutter mounted thereon, a work sup port on said base, feed mechanism for relatively moving said cutter and support toward each other, said feed mechan including a driving pinion, a power-driven differential planetary mechanism for operating said pinion, a brake for controlling said planetary mechanism, a treadle to operate said brake, locking means for automatically and positively. locking said driving pinion in. one position of said support, and means controlled by said treadle to release said lochillg means to permit relative movement by gravity of. said cutter and support away from each. other.

6. A mortiser comprising in combination, a: base,.a cutter mounted thereon, a work support movably mounted on said base, feed mechanism for moving said support toward the cutter, an oscillatory member for moving said support, a pinion engaging gear teeth on said member, and means to rotate said pinion, said means comprising a power-operated difierential. planetary mechanism controlled by a brake.

'Z. Amortiser comprising in combination, a base, a. cutter mounted thereon, work support. on said. base", feed mechanism for relatively moving said cutter and support toward each other, an oscillatory member for moving one. of said members on said base, a pinion engaging gear teeth on said oscillatory member, means to rotate said pinion, said means comprising a power-operated differential planetary mechanism, a brake for controlling said mechanism, a treadle to operate said brake, said cutter and said support being separated by gravity, and automatic means for positively locking one of said parts in fixed position relative to the other.

8. Feed mechanism for a work support for a wood working machine comprising in combination, an oscillatory member connected to said support so that oscillation thereof will movesaid support, a driving pinion connected to said member, means torotate said pinion in one direction to advance said support toward a cutter, means to release the rotating means for said pinion to permit movement by gravity of said support in the opposite direction, and means toloclr said support in 0perative position.

9. Feed mechanism for a work support for a. wood. working machine comprising in combination, an oscillatory member connected to said support so that/oscillation thereof will move said support, a driving pinion connested: to said member, means to rotate said pinion in one direction to advance said sup port toward acutter, a clutch in the driving mechanism for said pinion, means to engage and disengage said clutch, and means to retain said support in elevated position with clutch disengaged.

10. Feed mechanism for a work support for a wood working machine comprising in combination, an oscillatory member "connected to said support so that oscillation thereof will move said support, a driving pinion connected to said member, means to rotate said pinion in one direction to advance said support toward a cutter, a clutch in the driving-mechanism for said pinion, means to. engage and disengage said clutch, means to lock said support in elevated position with said clutch disengaged, and means to release said locking means.

11. A mortiser comprisingin combination, a base, a cutter mounted thereon, a support movable on said base toward and from said cutter, an oscillatory member, an adjustable connection between said oscillatory member and said support, means to oscillate said member in one direction to move said support toward said cutter, a drivingpinion for actuating said oscillatory member, locking means forv retaining said pinion and oscillatory member in one position, and means to render said locking means inoperative.

12. A mortiser comprising in combination, a base, a cutter mounted thereon, a support movable on said base toward and from said cutter, a driving pinion operatively connected to said support for eiiecting movement thereof in one direction, power-driven diii'erential planetary mechanism for rotating said pinion, brake means to control said mechanism, said support being moved by gravity in the opposite direction, and locking means for automatically and positively locking said support in operative position.

13. A mortiser comprising in combination, a base, a cutter mounted thereon, a support movable on said base, an oscillatory member within the base, an adjustable connection between said oscillatory member and said support, power-driven means for actuating said oscillatory member in one direction to move said support toward said cutter, said support being moved away from said cutter by grav= ity, and lockingmeans for automatically and positively locking said support in operative position.

14. In a machine of the character described, a power-driven revolving cutter and a work Support, a power-driven. machines feed mechanism for moving one of said mem bers toward the other, means for automatically and positively locking said one member in position when said one member reaches its point of closest approach toward said other member, and means for releasing said locking means so that said one member will move away from saidother member by gravity.

15. A chain mortiser, comprising a. power.- driven chain cutter and a work support, power-driven machine-feed mechanism for moving one or" said members toward the other, means for automatically and positively looking said one member in position when said one member reaches its point of closest approach toward said other member, and means for releasing said locking means so that said one member will move away from said other member by gravity,

16. A mortiser having a movable work sup port and operating means whereby said support is lifted and dropped, said support being lifted by a power-driven machine-feed mechanism and dropped by gravity, and means to automatically and positively lock said support in its raised position.

17. A mortiser having a movable work support and operating means whereby said support is lifted and dropped, said operating means including an oscillatory lever movable to lift said support and a power-driven pinion engaging with said lever, said support being dropped by gravity, and means to automatically and positively lock said support in its raised position.

18. A mortiser having a movable work support and operating means whereby said support is lifted and dropped, said operating means including an oscillatory lever movable to lift said support and a power-driven pinion engaging with said lever, said support being dropped by gravity, an adjustable connectlon between said lever and said support, and means to automatically and positively lock said support in its raised position.

19. A mortiser having a movable work support and operating means whereby said support is lifted and dropped, said operating means including an oscillatory lever having a geared segment at each end thereof, the geared segment at one end of said lever meshing with a rack on said work support and the geared segment at the other end of said lever meshing with a power-driven pinion, said support being dropped by gravity, and means to automatically and positively lock said support in'itsiaised position. 7 s r 20. A mortiser having a movable work support and operating means whereby said support is lifted and dropped, said support being lifted by power-driven machine-feed mechanism and dropped by gravity, a clashpot for checking the fall of said support, and means to automatically and positively lock said support in its raised position.

21. A mortiser having a movable work support and operating means whereby said support is lifted and dropped, said operating means including an oscillatory lever movable to lift said support and a power-driven clifferential planetary mechanism operable to move said lever, said support being dropped by gravity, and means to automatically and positively lock said support in its raised position.

22. A mortiser having a movable work support and operating means whereby said support is lifted and dropped, said operating ieans including a power-driven machinefeed mechanism for lifting said support and a mechanism to automatically disengage said feed mechanism from the source of power when said support reaches a predetermined position, said support being dropped by gravity, and means to automatically and positively lock said support in its raised position.

23. A wood working machine comprising, in combination, a base, a power-driven cutter mounted thereon, a work support movable on said base from and toward said cutter, power-driven machine-feed mechanism for moving said support toward said cutter, said support moving away from said cutter by gravity, automatic locking means to positively lock said support in operative position, means to release said locking means, and automatic means to render said locking means inoperative while said support moves away from said cutter.

24. A wood working machine comprising, in combination, a base, a power-driven cutter mounted thereon, a work support movable on said base from and toward said cutter, power-driven machine-feed mechanism for moving said support toward said cutter, said support moving away from said cutter by gravity, automatic locking means to positively lock said. support in operative position, means to release said locking means, autom; means to render said locking means inoperative while said support moves away from said cutter, and automatic means to render said locking means operative when said support moves toward said cutter.

25. A wood working machine, comprising, in combination, a base, a power-driven cutter mounted thereon, a work support movable on sait base from and toward said cutter, powerdriven machine-feed mechanism for moving said support toward said. cutter, said support moving away fr a said gravi v, automatic locking means to positively lock said support in operative position, means to release said locking means, automatic means to render said locking means inoperative while said support moves away from said cutter, and a weighted member which is moved by said feed mechanism when said support moves toward said cutter and which operates by gravity to render said locking means operative.

26. A wood working machine, comprising, in combination, a base, a power-driven cutter mounted thereon, a work support movable on said base from and toward said cutter, powerdriven machine-feed mechanism for moving said support toward said cutter, said support moving away from said cutter by gravity, a ratchet wheel gear-connected to said support, a pawl engaging with said ratchetwheel at the end of each cut, means for tripping said pawl, and a pawl latch for holding said pawl in its tripped position while said support is moving away from said cutter.

27. A wood working machine comprising, in combination, a base, a power-driven cutter mounted thereon, a work support movable on said base from and toward said cutter,

J. cutter mil power-driven machine-feed mechanism for moving said support toward said cutter, said support moving away from said cutter by gravity, a ratchet-wheel gear-connected to said support, a pawl engaging with said ratchet-wheel at the end of each cut, means for tripping said pawl, a pawl latch for holding said pawl in its tripped position while said support is moving away from said cutter, and automatic means for releasing said pawl from said pawl latch when said support moves toward said cutter.

28. A wood working machine comp ising, in combination, a base,'a power-driven cutter mounted thereon, a support movable on said base from and toward said cutter, a powerdriven machine-feed mechanism for moving said support toward said cutter, said support being moved away from said cutter by gravity, a ratchet-wheel gear-connected to said support, a pawl engaging said ratchet-wheel at the end of each cut, means for tripping said pawl, a pawl latch for holding said pawl in its tripped position while said support is moving away from said cutter, and automatic means for releasing said pawl from said pawl latch when said support moves toward said cutter, said automatic means comprising a weighted member which is moved by said feed mechanism when said support moves toward said cutter and which operates by gravity to release said pawl from said pawl latch.

ROBERT S. BROWN, 

